Sunday, 28 September 2014

Scratchbuilding tutorial part 3: How to build

And finally we arrive at the third and final part of my little series on scratch building. This will part will deal with the basics of handling, cutting and scribing panel lines on plasticard.

Anyway let's start with making your first part. Here I've used a leftover 1mm plasticard strip that I cut from a larger sheet. Place the ruler where you want to make the cut, take your favourite cutting implement and drag it along the intended line, putting some pressure on the knife. Do NOT cut all the way through!

The picture above shows the resulting cut. Not very much to look at, but it will more than suffice for what comes next.

Next you take the plasticard piece in question and firmly bend close to the cut until it snaps. This is by far the fastest and most efficient way to handle plasticard. On thinner pieces like 0.13 and 0.25mm thick plasticard you can often just cut all the way through with little effort but that will be not sufficient for thicker plasticard. In fact, fact when cutting really thick plasticard you should utilize your scribing tool as well.

Here I have a 2mm thick leftover piece. The procedure is almost the same just with an additional step. First, before using the knife, you make a grove with your scribing tool. Just take the tool and drag it towards you while putting pressure on it. The point on the 'hook' is what does all the work so take care to not damage it.

When you have your groove, just repeat the steps showed earlier. While strictly not necessary, cutting with the knife inside the grove will help with the snapping procedure. In this case I also took the opportunity to make some panel lines on top of the part. Unfortunately they are not very visible in the above pictures but making them couldn't be simpler. Just use the scribing tool as mentioned above but use less pressure than before.

Using a scribing tool without a ruler or some kind of guide is not something I can recommend but sometimes it has to be done. Even worse is any kind of rounded surface or indeed a tube or pipe! For these situations I've developed the following method. First I use some masking tape that I make a couple of layers thick. This forms my 'ruler' and I tape it along the line I wish scribe. Secondly I take a normal knife and score the line. After that I take the scribing tool and slowly push it away from me along the previously scored area. This widens the line and makes it possible to start using the scribing tool as it was intended. It is a slow and fickle process and not always entirely successful but it is certainly better than doing it freehand.

A common problem when cutting plasticard, which is especially pronounced with thicker plasticard, is that the plastic tend to curl upwards and away from the cut. This is understandable as the material has to go somewhere and the path of least resistance is away from the knife. You'll have to excuse my poor drawing skills but the above picture shows a basic view how it looks from the side. This can be very hard to spot before you start painting as white plastic just doesn't produce enough shadows to properly highlight these areas. As a precaution, it is a good idea to always scrape a knife along the edge of any cuts.

Another problem is that the cut is often not as smooth as one would like and yet again it is a problem more pronounced with thicker plasticard. The first picture above shows the end of the 2mm piece I cut earlier and the second one shows an exaggerated profile view. Always be prepared to file and sand every piece you make. Part of this can be alleviated by using a saw but that option isn't always available, especially on a really big pieces.

When you have your pieces ready it is time to start assembling them. In the above picture I've used the previously cut pieces to form a simple L-shape. These two pieces were simply glued together with plastic cement. Of course, even the fastest curing plastic cement can take some time before the process is finished. This is both a strength and a weakness. A strength in that before it has hardened completely you can still reposition the pieces slightly. However it's a weakness when you just need something you've built to hold up itself very quickly.

In the second situation I usually put a dab of super glue inside the join and spray it with some accelerator. Instant curing and provides pretty good stability as well. Of course, in other situations you need to strengthen the join between pieces and I usually go for some square plasticard. Angles are available and while they are better than squares, you get half the amount compared to squares. On particularly large builds you might need internal structures to hold everything up but I couldn't possibly advice you on what to use, it all depends on the build after all.

When the shape is finished you need to start consider filling and sanding. No matter how well you prepare a piece there will always be a chance that it wasn't perfect. Most commonly this will show along any seams so it's there you need to concentrate your efforts. While I haven't done it in the above picture I would have first filed down or cut away any excess material, and put filler, like Milliput or Green Stuff, along the seam. When cured, this would later be sanded down and filled again if there was a need for it.

Finally I will spend a few words on economical use of plasticard. Whatever you do, don't cut plasticard as can be seen on the left sheet. That leaves strange and unusable shapes and makes it hard to cut more pieces with precision. It is far better to cut long, straight strips and put the leftovers from the strip in your leftover box. The sheet on the right should be proof enough. It started as a full sheet of plasticard that I have cut several strips of differing sizes from until it's about a third left of it. However, unlike the sheet on the left, I will have no problems cutting any additional pieces from it.

And that concludes my tutorial. It is my hope that this will help any beginners to start up their own pieces of art. Until next time!


  1. Your tip on how to cut plasticard really helped me last week! Sadly, i have a sheet of plastic card that looks like the left one on your last picture. But I don't use it much, only for bases and such. So I will have to make due with this sheet.

    1. I'm glad you found the tutorial helpful. Now go forth and create something awesome my padawan! :)